The “special relationship” was not supposed to look like this. On both sides of the pond, governments are wracked by chaos and paralysis.

In Washington, an attempt by President Donald Trump to get funding for his border wall has triggered the longest federal government shutdown in United States history. In London, Prime Minister Theresa May clings to power, even after seeing her Brexit deal suffer an historic defeat in Parliament this week that would have felled earlier governments.

The sense of crisis mounts. Security forces patrolling American waters and safeguarding American ports of entry are now working without paycheques — and are furious about it. In anticipation of a catastrophic “no-deal” Brexit in ten weeks, May’s government said it would mobilise army reservists to help deal with the untold headaches that crashing out of the European Union will bring.

The natural workings of democracy are under pressure. The Speaker of the House sought to postpone Trump’s annual State of the Union address; the President retaliated by scrapping her congressional trip to Afghanistan, where she and a bipartisan delegation were due to visit US troops. Democrats and Republicans have dug in their heels as distrust between the parties deepens.

In Britain, all paths forward threaten further uncertainty and rancour. The imperative to abide by the narrow results of the 2016 Brexit referendum has pushed a slow-moving constitutional crisis into its third year and could still lead to the implosion of May’s Conservative Party.

Majorities in both countries have clear feelings: most Americans oppose the government shutdown; most Britons do not want to leave the EU without a deal in place. But the hard-bitten nationalism of some voters has driven both countries to a cliff’s edge. Trump’s decision to pander to his hardline base has led him to embrace political brinkmanship. Neither May nor her chief opponent, Labour leader Jeremy Corbyn, is calling for the option many think would make the most sense — a second referendum — out of fear of the furious reaction from Brexiteers.

“Rarely have British and American politics seemed quite so synchronised as they do in the chilly dawn of 2019, three years after the victories of Brexit and Donald J. Trump upended the two nations’ political establishments,” wrote Ellen Barry and Mark Landler, of The New York Times, last Saturday. “The countries seem subject to a single ideological weather system — one that pits pro-globalisation elites against a left-behind hinterland.”

They point to the now-familiar story: the effects of the 2008 global financial crisis accentuated the divides between those in metropolitan centres and depressed post-industrial towns. Anger among the latter fuelled both Trump and Brexit.

“The people in those areas just said: ‘OK, we’re not giving them any more time, the people in London and DC, your time is up. We’re not going to wait a few more years for a recovery,’” Michael Lind, the author of Land of Promise: An Economic History of the United States, told the Times,/i>. “They decided: ‘There’s a limited pie. This pie is not growing.’”

But it has become painfully clear that neither Brexit nor Trump will redress these economic anxieties. Trump’s trade wars and tax cuts have, in many instances, hurt those whom he promised to uplift. He instead wages a culture war, conjuring a crisis on the border that’s largely unsupported by fact.

Brexit, too, was provoked by the illusory visions of politicians. The years since the referendum have proved that there can be no easy divorce with the European Union — and that life outside the continental bloc may be far more bleak and lonely than imagined.

At a town hall this week on the other side of the English Channel, French president Emmanuel Macron flatly declared that “the British people were sold a lie”.

Others see an even darker plot — the shadow of the Kremlin. The paralysis in both countries “adds up to a strategic bonanza for Vladimir Putin and his vision of a revanchist Russia”, wrote the Daily 202’s James Hohmann. “We don’t know exactly how much Moscow spent supporting influence operations to impact the UK and US elections in 2016, but it seems hard to overstate how good the Kremlin’s return has been on what Western intelligence agencies believe was a relatively modest investment.”

For Britain, there is a sense of historical comeuppance. The Brexiteers campaigned on the fumes of imperial delusion, promising a future in which Britain reclaimed its global pre-eminence once free of its ties to Brussels. Instead, that very colonial legacy now haunts its political present.

“Partition — the British Empire’s ruinous exit strategy — has come home,” wrote Indian left-wing writer Pankaj Mishra. “In a grotesque irony, borders imposed in 1921 on Ireland, England’s first colony, have proved to be the biggest stumbling block for the English Brexiteers chasing imperial virility. Moreover, Britain itself faces the prospect of partition if Brexit, a primarily English demand, is achieved and Scottish nationalists renew their call for independence.”

In the United States, other chickens are coming home to roost. The American public largely fault Trump for the present crisis and see through his efforts to blame the Democrats. That is partially because previous shutdowns have also been a Republican legacy.

“The GOP’s proclivity for using government shutdowns to force through its agenda is another example of its drunken frat-boy antics,” wrote Washington Post columnist Max Boot. “The three longest government shutdowns in US history were all caused by Republican temper tantrums.”

Gary Cohn, Trump’s former top economic adviser, told The Boston Globe that the shutdown was “completely wrong”, adding that he was “confused” about the course of White House strategy.

“I don’t understand what the outcome is here,” he said, “and I don’t understand where we’re going with it.”

It is a feeling of uncertainty that stretches across the Atlantic.

• Ishaan Tharoor writes about foreign affairs for The Washington Post. He previously was a senior editor and correspondent at Time magazine, based first in Hong Kong and later in New York